68 years after the bomb was first dropped on Hiroshima on 6Aug 1945 and on Nagasaki on 9Aug, nuclear weapons remain the single most dangerous short – term threat to what we call ‘civilisation’, and in theory at least, to humans as a species.

The just under 2000 nuclear weapons that the US and Russia maintain on high alert, launch-able in ‘a few dozens of seconds’ according to Russian Colonel Valery Yarynich, would create over 1-2 billion immediate casualties and bring about climatic conditions colder than the last ice – age according to climate researchers.

India and Pakistan face each other with over 100 weapons each, and the Pakistani arsenal is the worlds most rapidly growing nuclear arsenal. An India-Pakistan nuclear exchange would create up to a billion deaths from global famine in its aftermath, as well as hundreds of millions of immediate casualties.

Global progress toward zero nuclear weapons, a legal requirement of the nuclear nonproliferation treaty, the worlds most widely signed treaty, is stalled with Russia unwilling to go very far unless the US abandons its missile defence program, and rabid pro-bomb sentiments on the right of the US political spectrum.

At the same time, global opinion remains all but unanimously in favour of going to zero, with language at the UN increasingly revolving around ‘catastrophic humanitarian consequences’ of nuclear weapons use. The UN has created an ‘open-ended working group’ to get around logjams elsewhere and map a pathway to global nuclear zero.

Hiroshima Day in Sydney has already seen a rally in Hyde Park. Two further events are coming. They are: